LMP91000: How to know if sensor is disconnected from the circuit

Jay Dikep

Part Number: LMP91000
Other Parts Discussed in Thread: ADS1100

Tool/software:

Greetings,

I am currently using the LMP91000 IC to interface with electrochemical gas sensors. The IC is powered with a 3.0V supply, and I have configured the internal reference voltage to 20%, resulting in an output of approximately 0.6V when a sensor is connected and no gas is present.

However, I’ve observed that the output voltage remains the same (~0.6V) even when the sensor is removed or reconnected to the board. Note that I am reading ADC count using ADS1100 but counts does not change. I have tested 3-4 different new sensors and result is same as I mentioned earlier. I would like to understand if this is expected behavior.

Additionally, is there a recommended method to detect whether a gas sensor has reached the end of its life (i.e., is dry or no longer functional)?

I would greatly appreciate your insights and support regarding these issues.

Thank you!

1 month ago

0 Jay Dikep 1 month ago

Prodigy 10 points

I have referenced this question and tested it. It works and detects the sensor but how can I check the sensor life. In the same question, it is mentioned that it is not possible to check sensor life using LMP91000 but is there any other way to do it. Alex Thompson Josh Wyatt

+1 Alex Thompson 1 month ago in reply to Jay Dikep

TI__Genius 12185 points

Jay,

Thanks for running that test, I'm glad it was able to work for you. Unfortunately there is no built in way for the LMP91000 to detect if the sensor health is failing. The best you can do is run the connection test periodically to verify that the sensor is connected and operational.

Thanks

-Alex Thompson

0 Jay Dikep 1 month ago in reply to Alex Thompson

Prodigy 10 points

Okay, Thank you for the reply.

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LMP91000: How to know if sensor is disconnected from the circuit